As is known per se, effluents of urban, industrial and agricultural origin can be treated biologically using suitable microorganisms (bacteria, etc.) that may or may not be naturally present in these effluents.
The principle of a biological treatment is to convert the organic effluents into carbon dioxide and water, with heat being given off. This principle enables a loss of matter.
Thus, during the biological treatment, the microorganisms feed on the organic effluents, allowing decomposition of the latter. The amount of microorganisms (also called biomass or biological sludge) increases as the degradation of the organic effluents progresses.
Depending on the type of biological treatment used, a more or less substantial, but always non negligible, amount of biomass remains.
This biomass constitutes waste for which the costs of exploitation (agricultural, etc.) or of elimination (incineration, etc.) are increasingly high.
During a biological treatment, the degradation of the biomass is generally carried out using natural ageing of the microorganisms (25 to 30 days).
Said microorganisms that have died naturally are assimilated (consumed) by younger microorganisms. At each cycle, the amount of matter will be reduced, with production of carbon dioxide, water and heat.
One technique for reducing the production of biomass consists in reducing the lifecycle of the microorganisms by carrying out destruction thereof.
One destruction technique consists in subjecting these microorganisms to high pressures, in processes of the continuous flow type, such as those taught by documents WO 01/016037 and WO 00/07946. This destruction is, in practice, incomplete.